Certification Standards and Design Issues for Rudder Control Systems in Transport Aircraft

摘要

A recent transport aircraft accident involving inappropriate rudder inputs by the pilot has led to a series of National Transportation Safety Board recommendations regarding certification. In particular, certification standards are sought that will ensure safe handling qualities in the yaw axis throughout the flight envelope, including limits for rudder pedal sensitivity. This study is described where the ultimate goal is to establish such standards. A review of current Title 14 Code of Federal Regulations Part 25 with regard to rudder control is undertaken. An analytical investigation of possible piloting tasks for certification is presented. The tasks reflect the philosophy of the Federal Aviation Administration Advisory Circular 25-7A Flight Test Guide for Certification of Transport Category Airplanes. A limited desk-top, human-in-the-loop simulation was conducted to support the analysis. A comparison of the pedal force/feel systems for three transport aircraft and four rotorcraft is presented. Two parameters for assessing the quality of pedal and rudder systems are discussed: a linearity index and the amount of lateral yaw acceleration per unit of pedal force input. For purposes of comparison, rudder (yaw) control requirements from military handling qualities specifications and standards are compiled.